Size control mechanism



Aug 14, 1945- R. s. ELBERTY, .1Rv 2,382,215

SIZEl CONTROL MECHANISM Filed Aug.' 12, 1941 3 Sheets-Sheet 2 :inventor Rasse-r s. ELBEery up.

Aug. 14, 1945. R. s. ELBERTY, JR 2,382,215

SI ZE CONTROL MECHANISM Filed Aug. 12, 1941 s sheets-sheet 3 nnentox Gttorneg memes Aug. 14,1945

UNITED STATES PATEN 1'v OFFICE SIZE CONTROL MECHANISM Robert S. Elberty, Jr., Waynesboro, Pa., assignor to Landis Tool Company, Waynesboro. Pa.

3 Claims.

This invention relates to size control mechanisms, particularlyof the type which do not make use of a member for engaging the machined surface during a machining operation.

This invention is similar to that disclosed in my copending application Serial No. 299,369 filed October 13, 1939, now Patent No. 2,280,692, granted April 21, 1942, and is shown as applied to a machine similar to that disclosed in Patent No. 2,248,172. However, certain parts have been redesigned, others rearranged, and additional functions added, all of which has' resulted in more accurate size control. For example, it has been found that more accurate resultsV are obtained if the air nozzle instead of the abutment is mounted on the pivoted member. Provision has been made also for resetting the feed actuated member so that in the event of slight wheel -wear the air nozzle will continue to function properly. If the wheel wear is slight, variation in work size will be slight. When the nozzle is released upon removal of a work piece from the caliper there will be only sufllcient movement toward the abutment to eifecta slight adjustment of same. If a grinding operation is started under such circumstances, the space between the nozzle and abutment is such that the-first contact' is closed and the feed rate is immediately reduced to finishing speed. By resetting the nozzle for each grinding operation, this difficulty has been overcome- Finally, the adjustment which determines the amount of advance for the abutment has been made moreaccessi'ble.

Figure 1 is a partial sectional end elevation of the wheel support, feed mechanism, and size control mechanisms.

Figure 2 is an end elevation partly in section and showing a. close-up of my size control mechanism.

Figure 31s a. partial plan view of the size control mechanism, grinding wheel support, and work support.

Figure 4 is a section alongA the line 4-4 of Figure 3.

Figure- 5 is a sectionalong the line 5-5 of Figure 3.

In the drawings, numeral lli indicates the bed of a grinding machine, Il a wheel support slidably mounted thereon for movement toward and from grinding position, I2 a hydraulic motor for moving said wheel support toward and from grinding position, and I3 a handwheel'and associated mechanism for adjusting the position of said wheel support. A" grinding wheel I4 is mounted on a spindle I6 which in tum is rotatably Asupported in a housing. I6. A pulley l1 at` 4the opposite end of said spindle is driven thru a. belt I8 from a jackshaft I9 and a motor not shown. A work piece 20 is rotatably supported* on a work drive spindle 2l by a chuck 22.

The size control mechanism consists essentially of two members, an air nozzle 30, and an abutment 40, against which said nozzle is directed. Said abutment consists of an elongated cylindrical member` slidably supported in a bushing 42 which is in turn supported ina tube-like guide member 43 forming a partof bed l0. A link M attached to abutment 40 is also connected to a. shaft 45 which extends toward the front of the machine.' By means of 'this arrangement the operator may adjust or reset abutment 40 manually.

Nozzle is part of a mechanism which consists of a member 3| slidably mounted on slide surface 32 on a frame work I4 which may or may not be a part of the bed` IIJ. A pair of arms 35 extend downwardly from said slide. Between said arms is pivotally supported on pivot points 36. a support member 31 for nozzle 30. Said nozzle is adjustably mounted in a slot 38 in said support member and held in adjusted position A by means of a nut 39 on a threaded portion thereof. Adjustment of said nozzle in said slot may be effected by means of adjusting screwMi. The upper portion or support 31 consists of two fingers and 5l which extend thru an opening in slide 3l. A dial indicator 54 is mounted on said slide adjacent finger 5I and adapted to be actuated thereby. At the front end of said slideis a hardened surface 52 which forms the anvil of a caliper mechanism. A pair of spaced vertical pins 53 having hardened points for engaging the groundsurfaceof a. work piece 2li are inserted in said slide. Finger 50 also having a hardened point for engaging a ground surface, is the movable portion of the caliper.

Attached to nozzle 30 is a connection 55 to a supply of air under pressure (not shown). Said connection has a handle 56 formed thereon so that i'lnger 50 may be withdrawn to release a work piece 20 from the caliper. A spring 51'suitably attached to support 31 and another part of slide 3l urges nozzle 39 toward abutment 40. Movement of support 31 about its pivot may be adjusted by screw in handle 56. Said screw` is adapted to engage a beveled surface 58 on the underside of slide 3| and thus` to limit the amount of movement of nozzle 30.

Air is supplied to nozzle 30 by any suitable means thru a lin'e soin which lsiinserted a venturi 8| in connection with a manometer tube support in line with said adjusting screw 61.

A hook-like member 69 on said support is positioned to engage the lower end of said vertical portion 65 to prevent excess movement of slide 3| to the left.

A belt guard 1|] at the pulley end of spindle housing |6 has a projecting hook-like member 1| adapted to engage lug 66 and advance said slide during the feeding movement of the grinding wheel support as described in detail in my copending application. l

` Operation A master race or one ground toexact size is placed on the caliper. The abutment bar 48 is retracted from nozzle 3l! by means of push bar 45. This will assure enough space between said parts that the mercury switch will not function during the set up or trial grinding operation.

` The unground or trial work piece is then placed in the chuck and the grinding wheel moved into grinding position. The wheel is fed by hand for the grinding operation until the work has been ground almost to the desired size.l

Slide 3| is thenpulled toward the front of the machine until members 66 and 1| are firmly in contact. y

The air gap between nozzle 3) and abutment v 40 is set by pulling bar 45 toward the front of the machine and thus shifting abutment 40 ton Ward nozzle 30 until the second contactl is closed dierence in indicator readings for successively ground pieces. Screw 60 is then backed o an additional amount equal to the -above determined wheel wear. When handle 56 is.released with no race on the caliper, this setting of screw 60 will permit nozzle 30 to engage abutment 40 and shift same by the amount of the wheel wear, that is, until screw 60 engages surface 58. rThis adjustment of abutment -40 is the compensation for wheel wear. If the rate of wheel wear changes, the above procedure must be repeated.

The trial piece which has just been ground is placed in the caliper and another unground race is placed in the chuck. `Handle 56'is depressed to increase the air gap between nozzle 30 and abutment 40. Said handle is held in depressed position until the wheel moves into grinding position, and then. slowly released. If mercury rises to the finish contact, the setting of screw -61 must'be changed so that when engaged by block v68 as the wheel moves from position'A to the extreme front or B position of wheel base slide 3| will be adjusted to increase the space between nozzle 3|! and abutment 40. This prevents premature operation of the sizing device especially where wheel wear is not great enough to cause a reset of abutment 40. The reverse movement from position D to position C is the same as the rapid portion of the movement from C to D. However, a feeding movement occurs after the rapid movement and therefore the reverse movement which begins at the point to y which the wheel and wheel support have advanced does not return all the way to position C but only a distance equal to the rapid movement toward D and therefore lug 68 will not engage screw 61 on this movement. After reset screw 61 has been set the device is ready to control the grinding operation accurately until anotherset up becomes necessary due to a change of wheels or size of work.

The trial piece which has been ground a slight amount under-size say .002. inch, is removed from the chuck and placed on the caliper. An unground piece is placed -in the chuck and the grinding cycle started.

As the wheel base moves to position B, lug

f 68 engages screw 61 and shifts slide 3| to increase close limits.

the space between nozzle 38 and abutment 66. When the wheel spindle is shifted axially to place wheel I4 in position C, projecting member 1| moves into operative relation with lug 66 on slide 3|. As wheel I4 moves. to position D'slide 3| and hence nozzle 30 are moved at the same rate and in the same direction due to the relation between members 66 and 1|.

The piece on the caliper which is .002 inch under-size sets the caliper to compensate for this undersize. Since the space between nozzle 30 and abutment 4l)- was determined first with a piece of exact size, the trial piece being .002 inch undersize will increase the spacing one half this amount or .001 inch. :This will allow the base and wheel I4 to move .001 inch further than during-the grinding of the piece now on the caliper, .plus the amount abutment 40 was shifted to compensate for lwheel wear.

From this point on, work pieces of the same size may be ground successively to size Within Any variation from size will correct' itself since each piece removed from the chuck is placed on the caliper and determines the setting of the size control mechanism for the next piece.

I claim:

1. In a grinding machine, a grinding wheel support, a. grinding wheel rotatably mounted thereon, a work support, mechanism for effecting a relative feeding movement between said supports, a size control mechanism having cooperating elements, one of which is held in a fixed position during a grinding operation, the other 'of which moves, with said feeding movementmeans responsive to the relative movement between said elements for controlling said feed- .ing the extent of said adjustment.

2. In a grinding machine. a grinding wheel support, a grinding wheel rotatably mounted thereon, a work support. mechanism for effecting a relative feeding movement between said supports, a size control mechanism having cooperating eiements, one of which is heldin a ilxed position during a grinding operation, the other of which moves with said feeding movement, means responsive to the relative movement between said elements for controlling said feeding mechanism, a pivoted member for supporting one of said cooperating elements, a caliper member forming a part of said pivoted member, said pivotally mounted element being operable in the absence of a work piece on said caliper for engaging the other size control element for adjnsting saine an amount corresponding to the advance in feed during the preceding operation, a stop on said pivotally ounted member, and means for adjusting to change the' amount of feed for the next operation.

aseaais 3. In a grinding machine, a work support, a wheel support, mechanism for effecting a relative positioning.. movement i between said sup.- ports, mechanism for efiecting a relative feeding movement between said supports, a size control mechanism comprising cooperating members oneof which is mounted on a slide and movable toward the other in response to a feeding movement of said wheel, means responsive to the relative movement between said members for controlling said feed mechanism, means operable to reset one of said cooperating members after each grinding operation to compensate for wheel wear, and additional reset means responsive to a preliminary part of said positioning movement to reset said sliding member in case wheel wear is not suiiicient tocanse resetting of said other' member.

ROBERT S. ELBERTY. Jn. 

